7.7.4 Troubleshooting when executing MDB (DB queue)

(a) When DB queue exists at the service component end

When error occurs in service component

The error which has occurred at the service component is not notified to the HCSC server and the service requester as error information. Error information is output at the service component machine end. The following figure shows the method of notifying an error when error occurs in service component:

Figure 7‒75:  Method of notifying an error when an error occurs in the service component

(b) When DB queue exists at the service requester end

When an error occurs from the HCSC server

The following figure shows the method of notifying an error when an error occurs from the HCSC server:

Figure 7‒76:  Method of notifying an error when an error occurs from the HCSC server

The errors shown in Figure 7-76 are as follows:

• Error 1: Invalid request parameter

• Error 2: Address (Location) not found, service adapter has stopped

• Error 3: Data transformation failed

• Error 4: Message sending failed

When any of Error 1~Error3 shown in the figure are detected in HCSC server, the error is notified to Reliable messaging on the HCSC server machine.

When Error 4 shown in figure is detected, you can select whether to notify an error to Reliable Messaging on the HCSC server machine or to transform the exception of error into a fault message in the service adapter. For details on how to select an error acquired when an exception occurs, see "7.11 Handling of an exception that occurs in the service adapter".

Messages of an error are output to the message log. Reliable Messaging outputs a message indicating the failure in message fetching from the local queue to a log on the HCSC server machine.

When an error is detected in the HCSC server, perform rollback at HCSC server end and again try fetching a message in the service component (invocation of service component).

When you perform rollback in message fetching on the HCSC server machine and frequency of rollback (frequency of message delivery) reaches the maximum value, that message moves to the dead message queue. When the dead message queue name is not set or when the dead message queue is not created, process of invoking the service component is re-executed without any limit. Therefore set the dead message queue name or when the dead message queue without fail.

Further, when the frequency of process re-execution specified in request-jms.rollback-count property of the HCSC server runtime definition file is exceeded, warning message (KDEC00049-W) is output.

For details on setup of Reliable Messaging, see "3.1.2 Setting up the software required for the execution environment". For details on Reliable Messaging, see"Reliable Messaging".

When error is detected in the service requester

The following figure shows the method of notifying an error when an error is detected in the service requester:

Figure 7‒77:  Method of notifying an error when an error is detected in the service requester

The error occurs when the service requester performs queuing of messages in DB queue is output at the service requester machine end.

When synchronous service component is invoked and error of user-defined exception occurs

The following figure shows the method of notifying an error when synchronous service component is invoked and error of user-defined exception occurs:

Figure 7‒78:  Method of notifying an error when synchronous service component is invoked and error of user-defined exception occurs.

Specify queue for response when the service component is invoked for standard reception of asynchronous (MDB (DB queue), the service component of synchronous SOAP adapter is invoked from standard reception of asynchronous (MDB (DB queue). If user-defined exception occurs at the service component end, message of error information is sent to queue for response (Common queue for sending). If you specify destination of common queue for sending in DB queue at the service requester end, you can acquire contents of error by fetching message from there.

You must create queue for response (Common queue for sending) in advance but, when settings of queue for response are not performed or when number of messages in queue for response is in excess and sending to queue fails, perform rollback for process within the HCSC server and messages are resent from common queue for receiving standard reception. (However, rollback is not performed for process at the service component end (Transaction)).

When frequency of rollback (frequency of message delivery) reaches the maximum value, that message moves to the dead message queue. When the dead message queue name is not set or when the dead message queue is not created, process of invoking the service component is re-executed without any limit. Therefore you must set the dead message queue name or the dead message queue.

(a) Client correlation ID

The client correlation ID is information set in program at the service requester end which performs the invocation request of service component at the time of request. This ID is used to support request message from the service requester and logs and traces managed in the HCSC server. Therefore, it is recommended to specify different ID for each request sent to the HCSC server. (You must specify the ID when creating the service requester). The following figure shows range inherited by the client correlation ID:

(b) Common message ID

This ID is assigned by HCSC server. This ID is used to identify logs or traces within HCSC server. The following figure shows range inherited by the common message ID:

(c) JMSMessageID

JMSMessageID is assigned by Reliable Messaging. This ID is output to logs or traces within HCSC server. The following figure shows range inherited by JMSMessageID:

# JMSCorrelationID or user specific information of property is not inherited.

(d) Thread ID

Thread ID is an ID assigned to each thread processed using J2EE container. The following figure shows range inherited by thread ID:

#

You must embed information to link to user message when linking to program at the service component end.